KONDUROS, J.: CarlJohnson appeals the trial court's finding
he was involved in a single accident instead of two accidents for purposes of
the underinsured motorist (UIM) coverage limits in his insurance policy. We
affirm.

PROCEDURAL
BACKGROUND/FACTS

Johnson
was driving to work on U.S. Highway 701 in Horry County around 5:30 a.m. Timothy
Hunter was traveling behind Johnson. A third party, Jose Dominguez, was
traveling the opposite direction on Highway 701 when his vehicle crossed the
center line into the path of Johnson's pick-up truck. Johnson swerved to the
right to avoid Dominguez. However, Dominguez's truck still hit him, turning Johnson's
truck sideways in the road. His airbags deployed and he unbuckled his seatbelt
to exit the vehicle. Before he could exit, Hunter's vehicle hit Johnson a
second time knocking him into the floorboard of his truck and causing him
serious injury.

Johnson sued Hunter for
negligence seeking to recover under his own underinsured motorist coverage with
State Farm Mutual Automobile Insurance Company. The trial court found the
events constituted one accident, limiting Johnson's recovery to the maximum
allowed for "each accident" under the State Farm policy. This appeal
followed.

STANDARD OF REVIEW

In an action at law tried
without a jury, the appellate court will not disturb the trial court's factual
findings unless they are not reasonably supported by the record. Townes
Assocs., Ltd. v. City of Greenville, 266 S.C. 81, 86, 221 S.E.2d 773, 775
(1976). An action to determine whether coverage exists under an insurance
policy is an action at law. Auto-Owners Ins. Co. v. Hamin, 368 S.C.
536, 540, 629 S.E.2d 683, 685 (Ct. App. 2006).

LAW/ANALYSIS

Johnson argues
the circuit court erred in finding a single accident occurred thereby limiting
recovery under his UIM coverage. We disagree.

Johnson's UIM coverage
sets limits for "each accident." Therefore, the parties are
concerned with what constitutes a single accident in the context of the
policy. South Carolina does not appear to have addressed this precise issue
but other jurisdictions have. Most courts have concluded the question whether
one or more accidents occurred should be evaluated under the causation theory.
The trial court employed the causation theory analysis and neither party
appeals that ruling. Therefore, it is the law of the case.[1]See ML-Lee Acquisition Fund, L.P.
v. Deloitte & Touche, 327 S.C. 238, 241, 489 S.E.2d 470, 472 (1997) (stating
an unappealed ruling is the law of the case and should not be reconsidered by
the appellate court).

"Under the
cause approach, the insured's single act of negligence is considered the
occurrence from which all claims flow." Am. Cas. Co. v. Heary, 432
F. Supp. 995, 997 (E.D. Va. 1977) (finding a single occurrence when insured
crashed into a sign and barrier causing telephone pole and wires to fall
damaging two other vehicles over a period of approximately one minute and
fifteen seconds). "Courts applying the 'cause' theory uniformly find a
single accident 'if cause and result are so simultaneous or so closely linked
in time and space as to be considered by the average person as one event.'" Ill. Nat'l Ins. Co. v. Szczepkowicz, 542 N.E.2d 90, 92 (Ill. App. Ct. 1989)
(citations omitted) (finding two accidents occurred when an automobile struck a
tractor trailer, blocking both lanes, and a second automobile did not strike
the tractor trailer until five minutes had elapsed and one lane had reopened).

When one
negligent act or omission is the sole proximate cause, there is but one
accident, even though there are several resultant injuries or losses. Hyer v.
Inter-Ins. Exch. of Auto. Club, 246 P. 1055, 1057 (Cal. Ct. App. 1926)
(finding a single accident when a negligent driver struck the insured's car
breaking off the steering wheel and the insured then collided with a second
vehicle). Taken in its usual sense, the word "accident" means a
single, sudden, unintentional occurrence and is used to describe the event, no
matter how many persons or things are involved. St. Paul-Mercury Indem. Co.
v. Rutland, 225 F.2d 689, 691 (5th Cir. 1955) (finding one accident when
the insured's truck negligently collided with a freight train, derailing the
train and causing damage to sixteen cars and owners). An accident or
occurrence in this context should be viewed from the perspective of cause and
not effect. Olsen v. Moore, 202 N.W.2d 236, 241 (Wis. 1972) (finding
one accident when the insured's vehicle struck two vehicles almost
simultaneously, and there was virtually no time or space interval between the
two impacts, and the insured never regained control over the vehicle prior to
striking the second automobile).

We could find no
South Carolina cases directly on point. However, in Sossaman v. Nationwide
Mutual Insurance Co., 243 S.C. 552, 135 S.E.2d 87 (1964), the court, in
dicta, recognized the majority view regarding whether a single accident has
occurred for purposes of insurance coverage.

A number of cases
support the general position that where one proximate, uninterrupted and
continuing cause results in injuries to more than one person or damage to more
than one item of property there is a single accident or occurrence within the
meaning of a liability insurance policy limiting the insurer's liability to a
certain amount for each accident or each occurrence.

Having considered
the rationale behind the causation theory and its application in other cases,[3] we now turn to its application in
this case. Johnson contends
two distinct accidents occurred in this case because the time between the first
and second impacts was "at least one and one-half to two minutes."
This is premised upon his conclusion it would have taken at least that long for
his airbags to have deployed and for him to remove his seatbelt. He maintains
the trial court erred in finding one accident without even making a
determination about exactly how much time passed between the two collisions.

Johnson places too much
emphasis on the timing of the impacts. Most cases discussing the causation
theory do not rely solely on the timing of events in determining whether or not
one or two accidents occurred. While timing is frequently a part of the analysis,
the courts place the most emphasis on whether or not one source of negligence
set all the subsequent events in motion. Szczepkowicz, 542 N.E.2d at 90, heavily relied upon by Johnson, involved
collisions occurring five minutes apart. The court recognized timing is only
one factor to be considered.

National argues that the time span between collisions is not a
factor this court can consider. This contention is without merit. Certainly
one occurrence can result in injuries suffered over a period of time; in such a
case, time would be irrelevant to a determination of the number of occurrences.
The relevance of time between injuries is relevant, however, under other
factual scenarios. In the instant case, the issue involves the reasonableness
of a driver's actions and his failure to take corrective measures after an
accident; the time span between collisions is one factor that must be taken
into account.

Id. at 93 n.3 (citations omitted) (emphasis added).

The question of whether a
single accident occurred under the causation theory will turn on the particular
facts of each case. The court will be required to look at all the
circumstances, including timing, in its analysis.

Turning to the record before
us, evidence supports finding the collisions resulted from Dominguez's single
act of negligence. Johnson testified approximately one and one-half to two
minutes passed between impacts. However, he also testified he "couldn't
pin it down to two whole minutes, but [he] kn[e]w it was time."

Hunter testified it felt like
two or three seconds between the impacts "cause it just happened."
He further testified he was traveling one and one-half to two car lengths
behind Johnson just prior to the accident, and he applied his breaks and
skidded approximately fifteen feet before hitting Johnson. Johnson and Hunter
both testified the highway had steady traffic on it at the time of the crash
giving rise to an inference another vehicle would have been between Johnson and
Hunter if they were actually one and one-half to two minutes apart.

Furthermore, Hunter was able
to testify about witnessing the initial impact between Dominguez and Johnson
indicating he was close enough behind Johnson to see the accident as it happened,
but did not have time to stop. Importantly, Johnson testified he did not
believe Hunter could have done anything to avoid hitting him. This statement contradicts
Johnson's assertion two accidents occurred and instead supports the finding
that Hunter's hitting the truck did not constitute a second, distinct negligent
act but was simply an additional foreseeable consequence of Dominguez's
negligence.

CONCLUSION

Under the causation theory,[4] evidence
in the record supports finding a minimal amount of time passed between the
impacts and the second impact was not due to Hunter's own independent
negligence but was a foreseeable consequence of Dominguez's negligent conduct.
Consequently, the ruling of the trial court is

AFFIRMED.

SHORT and
THOMAS, JJ., concur.

[1] Because the
parties do not dispute analysis under the causation theory is appropriate, we
are not called upon to determine whether South Carolina would adopt that
analysis in similar cases. However, a review of relevant case law is necessary
to understand the causation theory and whether the trial court properly applied
it to the facts of this case.

[2] In Sossaman,
the court was not required to determine whether a single accident occurred.
In that case, the
parties were arguing over the limitation of $5,000 per personal injury when wife was injured in a school bus accident and she and husband made claims
for personal and property injury and loss of consortium respectively.

[3] Most cases from
other jurisdictions discuss accident in the context of a liability policy.
However, the rationale behind the causation theory still seems applicable when
considering UIM coverage. One case espousing the causation theory maintains
the very existence of limits means the parties to the insurance contract
contemplated a cap on benefits for their own negligent actions. Under the
effect theory, liability could be limitless depending on the number of parties
injured. SeeSt. Paul-Mercury Indem. Co. v. Rutland,
225 F.2d 689, 692 (Ga. 1955). Likewise, the parties contemplate a limit to UIM
coverage for the negligence of other underinsured motorists whose actions could
result in injury to the UIM holder by multiple parties.

[4] In Hartford
Accident & Indemnity Co. v. Wesolowski, the court
characterized its approach to this issue as the "event test," providing
the test for determining whether there has been one accident within a liability
policy is if there has been but a single event of an unfortunate character that
took place without one's foresight or expectation. 305 N.E.2d 907, 910 (N.Y.
1973) (finding one occurrence when the insured vehicle struck an oncoming
vehicle then ricocheted off and struck a second vehicle more than one hundred
feet away a second or two later). Under either the causation test or the event
test, the result in this case would be the same.